(a) Field of the Invention
This invention relates to a method and means for mediating the physiological effects of peptide hormones, neurotransmitters, drugs and chemotactic agents as well as the agonists, antagonists and synthetic analogues of these compounds. It also relates to the novel such mediating agents.
There are many hormones and neurotransmitters which have a physiological effect on the human body. The following are some examples:
Adrenocorticotropin hormone (ACTH) is a 24 amino acid-residue-long pituitary hormone which stimulates the secretion of adrenal cortical steroids and induces growth of the adrenal cortex.
Angiotensin is a hormone which acts on the adrenal gland to stimulate the release of aldosterone. It causes contraction of the smooth muscle. The amino acid sequence of horse angiotensin II is EQU Asp-Arg-Val-Tyr-Ile-His-Pro-Phe.
Vasopressin and oxytocin belong to the neurophyseal family of peptide hormones. Both are 9-residue-long peptides containing a disulphide bridge and an amidated C-terminus. ##STR1##
Vasopresin has antidiurtetic and vasopressor effects while oxytocin induces contraction of smooth muscles, especially in the uterus and mammary glands.
Bombesin is a linear tetradecapetide hormone responsible for a wide range of biological activities. The latter include its action on the central nervous system as a stimulus to disrupt thermo-regulation causing the release of other hormones, e.g., insulin, glucagon, gastrin, prolactin and growth hormone and its stimulation of mitogenesis.
Bradykinin is a hormone belonging to a group of hypotensive peptides known as plasma kinins. It acts on smooth muscle, delicate peripheral vessels and increases capillary permeability. Its amino acid sequence is EQU Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg.
.beta.-casomorphin (Tyr-Pro-Phe-Pro-Gly-Pro-Ile) is a peptide hormone with opioid activity.
Cholecystokinin is a polypeptide hormone which causes gallbladder contraction. It stimulates the release of calcitonin and glucagon.
Met-enkaphalin and Leu-enkaphalin are pentapeptide hormones in the brain possessing opiate-like activity. The Met-enkaphalin shares a common precursor with ACTH and .beta.-lipotropin. Its structure is: EQU Tyr-Gly-Gly-Phe-Met.
The endorphins are derived from .beta.-lipoprotein and elicit reactions, e.g., analgesia, behavioral changes and growth hormone release.
Gastrins are heptadecapeptide hormones which are highly potent gastric secretion stimulants. The amino acid sequence of human gastrin I is EQU 5-oxo-Pro-Gly-Pro-Trp-Leu-Glu-Glu-Ala-Tyr-Gly-Trp-Met-Asp-Phe-NH.sub.2.
Glucogen is a polypeptide hormone produced in the alpha cell of the islets of Langerhans in the pancreas, which appears to be present in increased concentrations in diabetes. Its amino acid sequence is EQU His-Ser-Gln-Gly-Thr-Phe-Thr-Ser-Asp-Tyr-Ser-Lys-Tyr-Leu-Asp-Ser-Arg-Arg-Ala -Gln-Asp-Phe-Val-Gln-Tyr-Leu-Met-Asn-Thr.
Insulin is a polypeptide hormone produced in the beta cells of the islets of Langerhans situated in the pancreas of all vertebrates. It is secreted directly into the bloodstream where it regulates carbohydrate metabolism, influences the synthesis of protein and of RNA, and the formation and storage of neutral lipids. The amino sequence of human insulin is ##STR2##
LH is a gonodotrophic hormone which stimulates the synthesis of progesterone in the ovaries. Together with FSH, it stimulates the release of estrogen from Graafian follicles. It also induces the process of ovulation in which the mature ovum is extruded from the follicle and, following this, the cells which hitherto surrounded it are converted under the influence of LH into lutein cells (corpus luteum). In the male, it stimulates the interstitial cells of testes to secrete testosterone.
Kentsin is a tetrapeptide hormone (Thr-Pro-Arg-Lys) with contracentive properties.
LHRH is a neurohumoral hormone produced in the hypothalamus which stimulates the secretion of the pituitary hormones. LH and FSH (follicle-stimulating hormone), which in turn produce changes resulting in the induction of ovulation. Its amino acid sequence is EQU pyroGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-GlyNH.sub.2.
Neurotensin is a 13-residue-long peptide hormone exhibiting activities, e.g., hypertension, hyperglycemia, gut concentration, increased vascular permeability, enhanced secretion of ogrwoth hormone and hypothermic activity.
Substance P is an undecopeptide belonging to a group of proteins named tachykinins characterized by contractile action on extravascular smooth muscle. It also acts as a vasodilator, depressant, and like bradykinin, as a pain-producing agent. It stimulates salivation and produces increased capillary permeability. Its amino acid sequence is EQU Arg-Pro-Lys-Pro-Gln-Phe-Phe-Gly-Leu-Met-NH.sub.2.
Histones are small protein possessing a rather open, unfolded structure attached to DNA of cell nuclei by conic linkages. The are not hormones but are used as controls in tests associated with the present application.
The entry of Ca.sup.2+ and/or Mg.sup.2+ in many excitable cells can be inhibited by the calcium-channel antagonists (or blockers) which are drugs of major therapeutic importance. These drugs represent quite diverse classes of organic compounds. Verapamil, diltiazem and nifedipine are three main calcium-channel antagonists which have proven valuable in treating cardiac arrythmias and coronary disease. They bind strongly to the excitable cell membranes. A large number of synthetic analogues of these three major drugs have been made with the hope of improving their effectiveness. As is the case with the peptide hormones and their analogues, a common property of the calcium-channel antagonists (called "the drugs" hereinafter) and their analogues including agonists and synthetic commpounds, is their ability to bind Ca.sup.2+ and/or Mg.sup.2+, which is present in millimolar concentrations in the extracellular fluid. The Ca.sup.2+ - and/or Mg.sup.2+ - bound form is therefore the bioactive conformation of the drugs and their analogues.
Chemotaxis of polymorphonuclear leukocytes is the directed migration of these leukocytes along a chemical concentration gradient. Several small peptides are known to exhibit chemotactic behaviour towards leukocytes (i.e. neutrophils and eosinophils). The folded .beta.-turn has been suggested as a conformation present in the free form of the naturally-occurring peptide chemoattractants. In addition to these, a large number of proteins, amino acids and synthetic peptides are chemotactic. One of the most active peptides is N-formyl methionyl-leucylphenylalanine (f-Met-Leu-Phe) and its derivatives.
These are only a few of the many naturally-occurring and synthetic agents, which effect a variety of physiological actions in the human body. It would therefore be desirable to provide a procedure and the means whereby the physiological effects of such naturally-occurring and synthetic agents may be mediated for the beneficial physiological effect it may have on the human body.
(b) Description of the Prior Art
U.S. Pat. No. 4,348,387 patented Sep. 7, 1982 by M. Brownlee et al provided a process and system for controlled delivery of a biologically active substance to an animal body fluid. The invention involved contacting fluid with a reversible complex of a conjugatae (1) and a binding macromolecule (2). The conjugate was a biologically-active portion which was intended to be proportionately released into a body fluid stream in response to varying concentration levels of a component of the body fluid stream, and a complexing substrate portion which conjugated with the biologically-active portion and which had affinity to the binding macromoleucle (2), competitively or non-competitively with the variable component of the body fluid. The component present in the body fluid was thus caused to complex to the binding macromolecule and thus to release the conjugate (1) therefrom into the fluid.
U.S. Pat. No. 4,392,996 patented Jul. 12, 1983 by L. A. Sternberger provided biologically-active peptide analogues by mixing a known biologically-active peptide with an affinity medium and separating the unknown peptide analogue by such techniques as liquid chromotography or electrophoresis. These biologically-active peptide analogues were found to react with receptors and thus to act as hormones which were said to have a more discriminating and longer lasting hormonal action than the original peptide.
U.S. Pat. No. 4,618,598 patented Oct. 21, 1986 by P. M. Conn provided a synthetic hormone complex having structure for binding to the surface of a cell and structure for altering second messenger mobilization by the cell. One form of the synthetic hormone complex functioned as an antagonist with specific binding affinity for a cell receptor of that hormone in combination with a calcium ion channel inhibitor. Another synthetic hormone complex functioned as an agonist comprising two or more molecules of a hormone having specific binding affinity for a cell receptor.
U.S. Pat. No. 4,668,772 patented May 26, 1987 by E. C. Lee provided a method for controlling the viscosity of protein hydrolysates by adjusting their magnesium and calcium content e.g. by reducing their viscosity by adding pyrophosphate or other precipitating agent to the hydrolysate and then removing the magnesium and/or calcium precipitate that was formed thereby. Alternatively, the viscosity may be increased by adding a magnesium- and/or calcium-containing source.
U.S. Pat. No. 4,680,283 patented Jul. 14, 1987 by D. F. Veber, provided analogues of substance P and eledoisin which were conformationally constrained by the presence of a lactam in the peptide chain. Such analogues were said to demonstrate greater analgesic, anti-inflammatory, antihypertensive, central nervous system agents, and stimulants of lachrymal secretion.
U.S. Pat. No. 4,701,521 patented Oct. 20, 1987 by H. J. Ryser et al provided a method of effecting cellular uptake of molecules which were either excluded from cells or poorly transported into cells, such molecules being covalently bonded to a cationic polymer which served as a transport carrier to transport the molecules into cells.